Peptide Reconstitution Dosing Calculation
After reconstituting 10 mg of peptide with 1 mL of bacteriostatic water, you will have a concentration of 10 mg/mL, and the volume you inject depends entirely on your prescribed dose in milligrams.
Understanding Your Concentration
When you add 1 mL of bacteriostatic water to 10 mg of peptide powder:
- The lyophilized powder contributes approximately 0.1 mL to the final volume 1
- Your total volume will be approximately 1.1 mL 1
- Your final concentration is approximately 9.1 mg/mL (10 mg ÷ 1.1 mL)
For practical purposes, most practitioners calculate this as 10 mg/mL, understanding there is minimal volume contribution from the powder at this scale.
Calculating Your Injection Volume
Use this formula:
- Volume to inject (mL) = Desired dose (mg) ÷ 10 mg/mL
Common Dosing Examples:
- For 1 mg dose: inject 0.1 mL (10 units on an insulin syringe)
- For 2 mg dose: inject 0.2 mL (20 units on an insulin syringe)
- For 5 mg dose: inject 0.5 mL (50 units on an insulin syringe)
- For 10 mg dose: inject 1.0 mL (entire vial)
Critical Safety Considerations
You must know your prescribed dose before injecting. The question "how much do I inject" cannot be answered without knowing:
- What specific peptide you are using
- What your prescribed therapeutic dose is in milligrams
- The intended route of administration (subcutaneous vs intramuscular)
Reconstitution Best Practices:
- Sanitize the vial stopper with 70% isopropanol before needle insertion 1
- Inject the bacteriostatic water slowly down the side of the vial to minimize foaming 1
- Gently swirl (do not shake vigorously) until powder is fully dissolved 1
- Inspect visually for clarity and absence of particulate matter before use 1
Storage and Stability:
- Label the vial with concentration, reconstitution date, and expiration date 1
- Store refrigerated at 2-8°C (36-46°F) 1
- Bacteriostatic water permits multi-dose use for up to 28 days when refrigerated 1
- Discard if discolored or contains particles 1
- Peptides are often unstable in aqueous solutions and should not be stored long-term without specific stability data 2, 3
Common Pitfalls to Avoid
- Never assume a standard dose - peptide dosing varies dramatically by compound and indication 4, 5
- Never use sterile water without preservative for multi-dose vials due to contamination risk 1
- Do not over-dilute - using more than 1 mL bacteriostatic water will reduce concentration and require larger injection volumes 1
- Maintain sterile technique throughout to prevent contamination 1
Bottom line: Contact your prescribing physician to confirm your exact dose in milligrams before injecting any reconstituted peptide.